Comparison of cancer study enrollments between urban, rural, frontier and remote participants.

Abstract

e13749 Background: In the United States (US), less than 5% of patients participate in cancer research studies, with community sites that serve rural participants generally having lower rates than academic centers. Unique barriers to enrollment for rural patients include lack of access to trial centers, cost of travel, and additional socioeconomic factors. We hypothesize that patients from rural (R), specifically those from frontier and remote (FAR) settings have disparate enrollment on cancer research studies based on study type compared to their urban (U) counterparts. Methods: 20,903 cancer study enrollments from 12,841 patients treated at Sanford Health, the largest US rural healthcare provider, were evaluated from 2013 to 2023. Patients over the age of 18 residing in SD, ND, MN, NE, IA, and WI were included. The primary outcome of enrollment on interventional trials was evaluated based on level of rurality (FAR, R, U). Secondary outcomes included enrollment by level of rurality based on study phase, type, multiple enrollments, and funding organization. Analyses of patient and disease characteristics, study phase (I-IV) and type (biobanking, therapeutic, screening, prevention) and funding organization (government, industry, academic collaboration, investigator-initiated) were also performed. Rurality was determined by geolocated patient addresses at the time of enrollment and rural-urban commuting area codes (RUCA) designation. FAR was determined by the US Department of Agriculture (USDA) definition, characterized by population size and geographic remoteness. Differences were examined using Kruskal-Wallis rank sum test and Pearson’s Chi-squared test. Results: Of 12,841 eligible patients, 52.1% (n = 6,695) were U, 25.7% (n = 3,294) were R and 22.2% (n = 2,852) were FAR. Demographic data was similar between groups in terms of race and sex, however FAR participants had a higher median age (59 vs 55 years, p < 0.001) and Native American participation rate (3% vs 1%, p < .001) than U. Interventional trial enrollment had the highest participation amongst FAR participants (21.7% FAR,18.4% R, 17.0% U, p < 0.001). Enrollment by trial phase and type was similar, except for lower FAR and R enrollment on prevention trials (0.8 % FAR, 1.6%% R, 11% U, p < 0.001). U patients had the highest rate of multiple study participation (3.5% U, 1.6% R, 2.8% FAR, p < 0.001). Government funded trials had significantly lower enrollment in both R and FAR participants compared to U (19% FAR, 17% R, 28% U, p < 0.001). Conclusions: Our comparative analysis reveals that FAR patients are more likely to enroll on interventional trials, while U patients had the higher participation rates in preventative studies and multiple studies. Lower FAR/R enrollment on government sponsored trials demonstrates a key area to expand outreach and access. Understanding these disparate enrollment patterns and strategies to increase FAR/R enrollments are needed.